Locomotive headlight



H. L. JOHNSTON LOCOMOTIVE HEADLIGHT Dec. 14 1926.

Filed Jan. 16, 1924 INVENTOR Howard Lc/ofimstm.

Ii ATTORNEY Patented Dec. 14, 1926.

"EJNITFE'ID er "'HoWARnL. JOHNSTON, or FOREST HILLS BOROUGH,'rnnnsynvanm, AssIGnoR To MANUFACTURING cciurnny, A. CORPORATION 01'"WESTINGHOUSE ELECTRIC &

PENNSYLVANIA.

LOCOMOTIVE :I-IEADLIGHT.

Application filed January 16,1924. Serial No. 686542.

service. As focusing is an operation which the ordinary workman is notable to perform and which cannotbe properly done except under specialconditions, it is necessary that the adjustment be maintained at leastas long as the life of the lamp element. When a new lamp is installed inthe headlight, a .new adjustmentof the focus is usually necessary.

Another requirement of a focusing device.

is that it shall be capable of adjusting the lampinto a plurality ofpositions in the reflector aperture. This is accomplished in part, by astraight line adjustment which permits the light to be placed at anydesired depth in the reflector aperture. and in part, byaba'll-and-socket joint which permits a circular movement of the lamp.

It is, therefore, one object of my invention to provide a focusingdevice which shall be capable of universal movement.

iA-nother object'of my invention is to provide-a focusing device wherebyone unitof the device shall be held in temporary adjustment while theother adjustment is being made.

Still another object of my invention is to provide a focusing device inwhich the parts shall be securely clamped when the lamp is in exactfocus in such manner that the adjusted parts shall not be displaced byreason of shocks and jars.

Heretofore, focusing means have been provided with devices which permituniversal movement of the parts. were used under conditions where thefixture was not subjected to shocks and jars, and consequently nospecial means for maintaining the lamp in focus was necessary. Focusingwas so seldom required that no special devices were needed to facilitatethe operation.

3, and

Many such devices are finally locked in position. Specifically,

I provide a lamp-supporting spindle which passes centrally through aball and-so'cket joint that is capable of universal movement.

The ball-and-socket joint is provided witha clamp and spring mechanismwhich holds it in movable frictional engagement while the spindle isbeing adjusted. The clamp and spindle are also provided with a pluralityof lock-nuts by means of which the adjusted parts are locked in apermanent manner.

Throughout the drawing, constituting a part hereof, in which likecharacters designate like parts,

Figure 1 is a view, partially in elevation and'partly in cross section.of a headlight with a focusing device therein;

Fig. 2 is a cross-sectional view oft-he clamp taken along the lineEDI-11 of Fig.

Fig. 3 is a plan view of the clamp shown in Fig. 2. v

' The headlight casing 1, show-n in Fig. 1, is provided with a reflectorQ and a lamp 3 therein that is'mounted in a socket 4 in a well knownmanner. Upon one end of a spindle 5 which is supported centrally in aball-and-socket member which has a ball portion 6' at one end and aflattened apertured portion or yoke 7 at the other end thereof. The endof the spindle 5 remote from the lamp isthreaded and projects throughthe apertured portion? ofthe ball member. 7

A knurled nut 8 is mounted on the spindle in the apertured portion ofthe ball member for moving the lamp along the axis of the spindle in onedirection. External to the 'apertured portion, a thumb nut 9, mounted onthe spindle is adapted to move the lamp in the opposite direction,andalso serves as a lock-nut for the spindle. A second thumb nut 10 ismounted on the spindle and serves as a lock-nut for the first thumb nut.A screw 11 in the ball member projects into a groove in the spindle toprevent the spindle from turning. partly in a clamp 12 and partly intherear wall 13 of the casing and, together with the A two-part socket isformed ball 6 fitted therein, comprises the ball-andsockct joint. Thejoint is held together by the clamp 12 which is hinged to a bracket 14:or clamp on the casing.

The clamp 1 1- is apertured and is provided with a centrally locatedsocket portion 15 which fits over the ball 6. Bit diametrically oppositepoints 16 of the aperture, the clamp is cut away in order to allow it tobe slipped over the flattened apertured portion 7 of the ball memberWhen the parts are assembled. In one end of the clamp, a countersunkopening 17 fits loosely over a bolt 18 in the easing. A. thumb nut 19screws on the bolt 18 against the clamp and prevents the ball frommoving. It coil spring 20 around the bolt 18 bears against the clamp 14:and holds the ball-and-soeket joint in temp rary engagement When thethumb nut 19 is not screwed down. A second thumb nut 21 is mounted onthe bolt and serves as a lock-nut tor the thumb nut 19.

The lamp is focused in the following inanner. Starting with all theparts released, the thumb nut 19 is screwed down until the spring 20bears against the clamp 12 sui iciently to hold the ball from moving.The spring is of such strength that it allows the ball to be moved andto be retained in any adjusted position. The longitudinal adjustment ofthe lamp is made by varying the position of the knurled nut 8 and thethumb nut 9 on the spindle 5. The spindle may be moved to very nearlythe correct position and held therein temporarily. The final adjustmentsare then made by varying the position of the ball in its socket in a.well known manner. lVhen the lamp is exactly in focus, the thumb nut 19is screwed tightly to lock the clamp in its final position, and the locknuts 10 and 21 are screwed down.

Although I have described a specific em bodiment of my invention, 1 donot limit it thereto, since various modifications thereof Wlll suggestthemselves to those skilled in the art, Without departing from thespirit of my invention, the scope of which is defined in the annexedclaims.

I claim as my invention:

1. In a light projecting device. a focusing device comprising auniversal joint member,

a lamp-supporting spindle axially disposed in said member and movablealong its axis, a spherical portion at one end and a flattenedaperture-d portion at the other end of said member, means in saidapertured portion 'lor adjusting said saindle, means e2;- ternal to saidapertured portion for adjusting said spindle, means for clamping saidmember, a nut for locking said clamping means and a spring bearing saidnutand clamping means for restraining the movement of said universaljoint member.

2. In a light projecting device, a focusing device comprising a socket,a ball member. a e amp, a ball on one end and a flattened aperturedportion on the other end of said ball member, a lamp-supporting spindlea1:- ially poiitioned in said ball member and slidable therein, nut insaid apertured portion r adjusting said spindle, a spindle adjust ingand locking ut external to said apertured portion, a nut to lock saidclamp and ly -ll member and a spring external to sa' 1 up bearing onsaid nut and clamp for maintaining said ball and clamp in frictionalengagement when the nut is loosened.

23. [r focusing device adapted to be mounted on a lamp casing havin anapertured socket in. one portion thereof comprising a threaded lampspindle provided with adjusting and locking nuts mounted thereon, asupport for said spindle having a ball member on one end thereof adaptedto be mounted in said socket and to form a closure for said opening anda flattened portion having an opening therein on the other end thereof,said flattened portion being adapted to permit the operation oi? one ofsaid adjusting nuts Within said opening and to pe nit the operation ofother adjusting nuts exterior thereto, said support having an axialopening therein coextensive with the opening in said casing whereby saidspindle is inserted into said casing through said support, and anapertured clamp attached to said casing and adapted to lock said supportand easing together. i

In testimony whereof, I have hereunto subscribed my name this 27th dayof December, 1923.

HOlVARD L. JOHNSTON.

